alsa

问题 I'm planning to implement a "DSP-like" signal processor in Python. It should capture small fragments of audio via ALSA, process them, then play them back via ALSA. To get things started, I wrote the following (very simple) code. import alsaaudio inp = alsaaudio.PCM(alsaaudio.PCM_CAPTURE, alsaaudio.PCM_NORMAL) inp.setchannels(1) inp.setrate(96000) inp.setformat(alsaaudio.PCM_FORMAT_U32_LE) inp.setperiodsize(1920) outp = alsaaudio.PCM(alsaaudio.PCM_PLAYBACK, alsaaudio.PCM_NORMAL) outp

问题 I'm using a raspberry pi, so it is sort of Debian (Raspbian) I have a synthesizer running (Zynaddsubfx) and I want to send him midi messages from code and have it playing the music for me. I will use ALSA for that. I managed to create a "emitting port" in my program by doing: snd_seq_create_simple_port(seq_handle, "My own sequencer", SND_SEQ_PORT_CAP_READ|SND_SEQ_PORT_CAP_SUBS_READ, SND_SEQ_PORT_TYPE_APPLICATION) now I can see ZynSubAddFX in aconnect -ol and my own sequencer in aconnect -il .

问题 I have this piece of a code and I want to work independently with each of the four mic array I use (Ps3 Eye Cam). For example I want to calculate cross-correlation between the mic 1 and the mic 4 excluding 2 and 3. How can I use channels I want? import audioop import alsaaudio inp = alsaaudio.PCM(alsaaudio.PCM_CAPTURE,alsaaudio.PCM_NONBLOCK) inp.setchannels(1) inp.setrate(8000) inp.setformat(alsaaudio.PCM_FORMAT_S16_LE) inp.setperiodsize(1000) Thanks 来源： https://stackoverflow.com/questions

问题 I'm trying to mix audio files via dummy card by using dmix and dsnoop: aplay s1.wav & aplay s2.wav & arecord -f dat -t wav -d 3 result.wav But is it possible? I have only dummy card by: modprobe snd-dummy My ~/.asoundrc file is: defaults.pcm.card 1 #dummy card pcm.duplex { type asym playback.pcm "dmix" capture.pcm "dsnoop" } pcm.!default { type plug slave.pcm "duplex" } Running on: CentOS6.5(x86_64) 回答1: The snd-dummy driver throws away playback data, and records silence. For a loopback

问题 I am using Android 4.2.2 on Qualcomm APQ8064 Chip set. I want to enable audio output to the USB headset. I tried using aplay command but no luck. The driver for usb-audio is already there in the code. Everything is integrated but i don't get any output on the usb-headset. Any flags that need to be set?? Any lead will be of great help. @Micheal:Following are the logs for the same, I just noticed that below logs from AudioUsbALSA can also be seen when the USB headset is not connected. 3502:I

问题 I am using Android 4.2.2 on Qualcomm APQ8064 Chip set. I want to enable audio output to the USB headset. I tried using aplay command but no luck. The driver for usb-audio is already there in the code. Everything is integrated but i don't get any output on the usb-headset. Any flags that need to be set?? Any lead will be of great help. @Micheal:Following are the logs for the same, I just noticed that below logs from AudioUsbALSA can also be seen when the USB headset is not connected. 3502:I

问题 I'm trying to write an application that needs either ALSA or OSS headers. Basically, I want to pass a define to the compiler if /etc/oss.conf does not exist, since that probably means the soundcard.h header doesn't exist (feel free to correct me on that one, I'm still new to working with OSS). Per the OSS documentation, you would use the include directive like so: include /etc/oss.conf CFLAGS := -I$(OSSLIBDIR)/include/sys One problem. OSS support is optional, so I'd want to check if the

问题 hey guys i'm trying to run a basic python speech to text code. This is the code. import speech_recognition as sr r = sr.Recognizer() with sr.Microphone() as source: audio = r.listen(source) try: print("You said " + r.recognize(audio)) except LookupError: print("Could not understand audio") The code works fine till it reaches the print stage and then throws this error. Is there anything that i have done wrong? ALSA lib pcm.c:2266:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.rear ALSA lib pcm

问题 Im attempting to use ALSA to take the input from a USB audio device and write it out to disk as a series of signed short values. What I'm ending up with are blocks of what appear to be valid data interspersed with large blocks of zeros. I'm guessing that I have my buffers setup incorrectly and am not using the memory mapping properly. What I'm trying: sample rate: 8K (this is forced by the device) buffer size: 2048 period size: 512 one channel The device appears to be opened properly and